Grease extraction ventilator

ABSTRACT

The grease extraction ventilator includes a water bath which is engaged by the air drawn from the cooking area over an upright front plate and down beneath a curved baffle, the lower end of which may be adjusted to cause the air to impinge against the water bath and push it upwardly against a concave deflector, with the entrapped grease and other products of combustion flowing, with water, over the upper edge of the plate at the rear of the water bath. Additional water droplets are thrown out of the air, while these droplets and moisture condensing on the top of the curved baffle cool the underside of this baffle, while flowing back to the water bath. A portion of the underside of this baffle is above the cooking area, and the cooling of the baffle tends to minimize the task of keeping it clean. The ventilator may be made in either the up-draft or down-draft form, while a safety baffle is held open by a cable and fused links, but closes when the temperature in the plenum melts the links. Makeup water is supplied during cooking, while a detergent may be placed in the water bath and the cold water therein replaced by hot water, the air flow carrying water droplets and detergent into the interior baffle arrangement, for cleaning purposes. The suction fan is then turned off, and hot water sprayed into the interior, to wash off any collection of grease and the like which has previously been acted on by the detergent. Thus, the inside surfaces of the ventilator do not require manual cleaning.

Unite States Patent [191 Molitor et a1.

[4 1 Oct. 15,1974

1 1 GREASE EXTRACTION VENTILATOR [75] Inventors: Victor D. Molitor,Denver; Arlen W;

Gallagher, Arvada, both of Colo.

[73] Assignee: Stainless Equipment (10.,

Englewood, C010.

[22] Filed: Dec. 11, 1972 [21] Appl. No.: 314,278

[52] US. Cl. 55/223, 55/244, 98/115 K [51] int. Cl Bold 47/02 [58] Fieldof Search 55/84, 95, 86, 239, 244, 55/248, 2231;98/115 K [56] ReferencesCited UNITED STATES PATENTS 3,055,285 9/1962 Gaylord 98/115 K 3,065,6871 1/1962 Graswich et a1. 98/115 K 3,370,404 2/1968 Lepper 55/2483,494,108 2/1970 Moragne 55/233 3,624,696 11/1971 Cohen et al. 55/2483,731,462 S/l973 Costarella et a1 55/228 Primary ExaminerCharles N. HartAttorney, Agent, or Firm1-1orace B. Van Valkenburgh; Frank C. Lowe [57]ABSTRACT The grease extraction ventilator includes a water bath which isengaged by the air drawn. from the cooking area over an upright frontplate and down beneath a curved baffle, the lower end of which may beadjusted to cause the air to impinge against the water bath and push itupwardly against a concave deflector, with the entrapped grease andother products of combustion flowing, with water, over the upper edge ofthe plate at the rear of the water bath. Additional water droplets arethrown out of the air, while these droplets and moisture condensing onthe top of the curved baffle cool the underside of this baffle, whileflowing back to the water bath. A portion of the underside of thisbaffle is above the cooking area, and the cooling of the baffle tends tominimize the task of keeping it clean. The ventilator may be made ineither the up-draft or down-draft form, while a safety battle is heldopen by a cable and fused links, but closes when the temperature in theplenum melts the links. Makeup water is supplied during cooking, while adetergent may be placed in the water bath and the cold water thereinreplaced by hot water, the air flow carrying water droplets anddetergent into the interior baffle arrangement, for cleaning purposes.The :suction fan is then turned off, and hot water sprayed into theinterior, to wash off any collection of grease and the like which haspreviously been acted on by the detergent. Thus, the inside surfaces ofthe ventilator do not require manual cleaning.

15 Claims, 18 Drawing Figures PAIENIEUBCT 1 1 4 3; 841 U62 SHEET 1 BF 5PAIENIEDnm 1 5mm SHEH 2 @F 5 PAIENTEB um I 51814 SHEEI 30? 5 GREASEEXTRACTION VENTILATOR This invention relates to grease extractionventila-' I tors, and more particularly to such ventilators for use withcooking equipment, such as stoves, ranges, broilers and the like.

Grease extraction ventilators for use with cooking equipment have beendeveloped through the years, so that such equipment is now availablewhich will operate satisfactorily under normal circumstances, but leavesmuch to be desired when unusual circumstances are encountered. Also,such equipment requires regular and laborious cleaning, normally byhand, in order to prevent an accumulation of grease in and about theventilator. An accumulation of grease in and about the ventilator ishighly undesirable, since it constitutes a very definite and dangerousfire hazard. However, due to the labor involved in cleaning suchventilators, many operators are inclined to scrimp on cleaning, therebypermitting a dangerous accumulation of grease. More recently, theproblem of air pollution has become a serious one. A grease extractionventilator, which does not successfully extract the grease, permitsgreasy vapors and similar contaminants to escape through the flue intothe outside air, thereby adding to the pollution burden on the alreadypolluted air which many persons breathe. Another problem encounteredwith grease extraction ventilators is that of actual fire on a broileror other cooking equipment which can become out of control, particularlyif there is any sort of grease accumulation in the interior of theventilator or in the ducts leading to the discharge flue. Greaseextraction ventilators are normally associated with a duct in which asuction fan pulls a sufficient volume of air through the ventilator thatsmoke and the like is removed from the cooking equipment. However, thisflow of air acts to suck any flames into the ventilator and therebyignite grease therein. Thus, although a tire damper can be closed, theheat may be sufficient that grease deposited beyond the damper willignite, thereby producing another tire, even though the original tire onthe broiler or other cooking equipment may be extinguished.

One of the particularly disagreeable tasks in cleaning prior greaseextraction ventilators is the necessity for the operator to open up theventilator and reach inside it, in order to clean the inside surfaces.Some of the ventilators are quite complicated in construction, while thesurfaces upon which grease might be deposited are not easy to reach,thus requiring considerable dexterity and contortionistic movements, inorder to reach and also adequately clean all of the interior surfaces.

Among the objects of this invention are to provide a novel greaseextraction ventilator, as for cooking equipment and the like; to providesuch a ventilator which extracts grease and cooking vapors as they areproduced, rather than permitting all of them to become deposited on theinterior walls thereof; to provide such a ventilator which is readilycleaned; to provide such a ventilator which includes a body of waterwhich is agitated by the air sucked through the ventilator and therebyremoves grease and vapors by both entrapment and condensation; toprovide such a ventilator in which the extracted grease and condensedcooking vapors are continuously removed; to provide such a ventilatorwhich does not require the operator to manually clean any difficult toreach inside surfaces thereof; to provide such a ventilator in which thefire hazard is effectively reduced; to provide such a ventilator inwhich flames from the cooking equipment which may be drawn into theventilator tend to be extinguished; to provide such a ventilator whichmay exist in more than one form; and to provide each such form ofventilator which is relatively simple in construction, reasonable incost and effective and efficient in operation.

The foregoing and additional objects, as well as the advantages andnovel features of this invention, will become apparent from thedescription which follows, taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view of a grease extraction ventilator,constructed in accordance with this invention, of the updraft type, withthe stove, broiler or other cooking equipment, as well as the exit ductor flue, being shown in dot-dash lines;

FIG. 2 is a front elevation of the ventilator of FIG. 1;

FIG. 3 is an end elevation of the ventilator of FIG. 1;

FIG. 4 is a transverse vertical section, on an enlarged scale,'takenalong line 44 of FIG. 2;

FIG. 5 is a transverse vertical section, on an enlarged scale, takenalong line 55 of FIG. 2;

FIG. 6 is an enlarged detail of a portion of FIG. 4, as indicated,showing particularly a drain cube for the water bath;

FIG. 7 is an enlarged detail of a portion of FIG. 5, as indicated, butshowing an adjustable baffle moved to a different position and also thecontour of the water bath during use;

FIG. 8 is a laterally condensed vertical section, on an enlarged scale,taken along line 8-8 of FIG. 3;

FIG. 9 is a fragmentary vertical section taken along line 99 of FIG. 4,showing particularly a plenum damper and a cable which normally holdsthe damper open and is provided with a fuse link;

FIG. 10 is a front perspective view of a grease extraction ventilatorforming another embodiment of this invention, of the downdraft type;

FIG. 11 is a front elevation of the ventilator of FIG. 10;

FIG. 12 is an end elevation of the ventilator of FIG. 10;

FIG. 13 is a transverse vertical section, on an enlarged scale, takenalong line 13--l3 of FIG. 11;

FIG. 14 is a transverse vertical section, on an enlarged scale, takenalong line 14l4 of FIG. 11;

FIG. 15 is an enlarged detail of a portion of FIG. 13, as indicated,showing particularly a drain cube and associated parts of the waterbath;

FIG. 16 is an enlarged detail of a portion of FIG. 14, as indicated, butshowing an adjustable baffle moved to a different position and also thecontour of the water bath during use;

FIG. 17 is a condensed lateral section, on an enlarged scale, takenalong line 17l7 of FIG. 12; and

FIG. 18 is a wiring diagram of an electrical control which may be usedwith the ventilator of either FIG. 1 or the ventilator of FIG. 10.

As illustrated in FIGS. 1-3, a ventilator V of this invention may bemounted in any suitable manner above cooking equipment E, such as arange, stove, broiler or the like, or a series of the same, with theside to side width of the ventilator corresponding to the width of thecooking equipment. The ventilator may be provided with a hook H having ashelf on the top thereof and a front, depending flange 11 thereof dis--posed directly above and forwardly of the front edge of the cookingequipment E. The cooking equipment is normally provided with. a backplate 12 which extends above the cooking level of the cooking equipmentE and is connected to the underside of the ventilator V at the rear edgethereof. A single side plate 13, as in FIG. 1, may form the end of boththe ventilator V and the hood H, although the hood I-I may be furnishedas a separate item of equipment, with a side plate 130 of the ventilatorand a side plate 13b of the hood, as in FIG. 3, being separate butconnected parts. A control box C is conveniently mounted on the shelf 10of the hood I-I, although it may be placed in any suitable posi tion,and is conveniently provided with a light switch 14 and a wash switch15. The light switch 14 is used to turn on and off a light, such as ofthe fluorescent type, which extends across the underside of the shelf 10of the hood I-I, while the operations which ensue after activation ofthe wash switch 15 will be described later. In addition to side plate13, the ventilator V is provided with a top plate 16, a front plate 17having an opening over which is installed a removable access plate 18,and a back plate 19. Access plate 18 is utilized primarily forinstallation or repair, and thus normally remains fixed in position,even during cleaning. The top plate 16 is provided with a rectangularopening in which is mounted a hollow, rectangular duct 20 which connectswith an outlet or exit duct D which leads to the flue of a chimney, andin which a suction fan of a conventional nature (not shown) isinstalled. Ordinarily, the suction fan is turned on at all times, exceptat certain times during the washing cycle, but is separately controlled.

The control box C may be provided with two compartments, in one of whichthe plumbing control valves are installed, as described later, and inthe other of which the electrical controls are installed, as describedlater. Both the plumbing controls and the electrical controls arestandard control equipment and thus are not shown, although adescription of what they are and their preferred sequence of operationis given later.

In accordance with this invention, as more particularly illustrated inFIGS. 4 and 5, the ventilator of this invention is provided with anupright plate 22 having an arcuate curl 23 at the top and extendingacross the front of the ventilator at its lower edge, being connected toa bottom plate 24 and extending upwardly therefrom. Extending rearwardlyand initially slightly downwardly from the lower edge of the front plate17 is a fixed baffle 25 which continues rearwardly and downwardly as anarcuate portion 26, which begins at a position spaced above, butslightly rearwardly from, a curl 23 of the upright plate 22. Preferably,the radius of curvature of arcuate portion 26 of the baffle correspondsto the distance from the center of the arcuate curl 23, so as to form achannel of substantially constant width curving arcuately around thecurl 23. The lower edge of arcuate portion 26 is disposed below but, ofcourse, rearwardly of the curl 23, while an arcuate, adjustable baffle27 having the same radius of curvature as fixed baffle 25, but a planarsegment 28 at its lower edge, is attached, as by bolts 29, to the fixedbaffle. The bolts 29 are inserted within vertical slots in the fixedbaffle 25 and extend through holes in the adjustable baffle 27, withnuts welded on the back side of the adjustable baffle, so that theposition of the adjustable baffle may be adjusted between an upperposition in which the planar segment 28 abuts the lower end of arcuateportion 26 of the fixed baffle, and the position shown, in which theadjustable baffle is fully extended. Ordinarily, the distance betweenthe upright plate 22 and the end of the planar segment 28 will be asshown in FIG. 7, i.e., approximately twice the minimum distancetherebetween, the latter being shown in FIG. 5.

For each installation, the position of adjustable baffle I 27 may bechanged, depending upon the normal water level, as hereinafterdescribed, the total width of the ventilator and the cubic feet of airadmitted, which are drawn through the ventilator by the suction fan,such as on the order of 250 cubic feet per minute for each lineal footof the width of the ventilator. In general, a throat section of lessercross sectional area is formed between the end of planar segment 28 andthe rear of upright plate 22, so as to increase the velocity of the airflowing at this point, for a purpose described below, with the airflowing into the ventilator through an inlet formed between curl 23 andthe underside. of baffle 25.

A water bath W having a normallevel indicated by the dotted line 30 ofFIG. 6, and the upper contour during use, indicated by the full line 31of FIG. 7, is maintained in the lower portion of the ventilator withinthe space determined by the bottom plate 24, the back plate 19 and theupright plate 22, as well as the side plates 13 or 13a. The normal levelof the water bath W, as in FIG. 6 is determined by the height of a draincube 32 which has an open top and is provided with a drain pipeconnection 33 which normally will extend through the rear wall 19, asshown, but alternatively may extend through the bottom wall 24, asindicated by the dotted line position 33a of FIG. 6. The open top of thedrain cube 32 receives any overflow of the water bath, with the centralposition of the drain cube, as in FIG. 8, insuring that overflow watercarrying grease and condensed vapor products will flow from each end ofthe water bath to the center, for substantially continuous removal ofgrease and condensed vapor products. A frontally concave, arcuatedeflector plate 34 extends, as in FIG. 8, from each end of theventilator to the area of the drain cube 32, along the lower rear of thewater compartment, with deflector plate 34 having either essentially thesame radius of curvature as the arcuate portion 26 and adjustable baffle27, or a slightly greater radius of curvature. Deflector plate 34 isattached to the bottom wall 24 by a series of lower tabs 35, as in FIGS.7 and 8, and to the rear wall 19 by a correspondingly spaced series ofupper tabs 36 of FIG. 7, in order to provide a space between the loweredge of deflector plate 34 and the bottom wall 24, as well as betweenthe upper edge of deflector plate 34 and the rear wall 19. The crosssectional area occupied by the tabs 35 and 36 is such as to offer nosignificant impediment to the flow of water beneath the lower edge ofdeflector plate 34, as well as down and behind the upper edge ofdeflector plate 34. Access to the drain is through removable plate 21,covering a hole in upright plate 22, as in FIGS. 2, 4 and 5. 1

In further accordance with this invention, as the air stream, whosevelocity is increased by the throat section between the end of planarsegment 28 and the upright plate 22, engages the water bath W, it willpush the water up against the deflector plate 34, as well as agitatingand whipping the surface of the water,

thereby churning the water quite violently and causing tongues of waterto move up into the air stream, as indicated in FIG. 7, to remove greasefrom the air stream, as well as condensed vapor products. Thus, theentire body of water W is forced up against the deflector plate 34.andwill overflow the upper edge of plate 34, to fall behind the plate andcarry with it retained grease and condensed vapor products. The contour31 of the water will become on the order of that shown in FIG. 7.although the water will tend to surge upwardly and downwardly as well,during the agitation by the air. Additional water vapor or droplets willalso enter the air stream and condense or coagulate, to be thrown outwhen passing around the upper end of a downwardly concave, essentiallyarcuate air deflector plate 38 which extends from generally opposite thelower edge of fixed baffle 25, to a point above the fixed baffle 25, asin FIGS. 4 and 5. Thus, water droplets containing condensed vapors orgrease which has not been removed by the previous action of the waterbath, will tend to be thrown out against the front plate 17, to dripback downwardly into the water bath along baffle 25. The upper edge ofplate 38 is maintained in position by a forwardly extending bracketplate 39 which is attached along its front edge to the top of a planarseg-- ment 40 of deflector plate 38 and along the rear edge of rear wall19 by a channel structure 41, which performs an additional functiondescribed later. It will be noted that the downwardly slanting planarsegment 40, along the upper edge of deflector plate 38 provides a throatsection which causes the velocity of air above fixed baffle 25 toincrease and causes the water droplets to separate when the air impingesagainst front wall 17, for subsequent return to the water bath byflowing along the top of baffle 25, which is coated by such flow.

The rear, lower edge of air deflector baffle 38 is secured to, butspaced slightly from, the back wall 19 by a spacing block 42 whichleaves a space at each end so that the water feed for replenishing thewater bath, due to evaporation or overflow into drain cube 32, may beintroduced at each end of the water bath, as in a manner hereinafterdescribed. Thus, the makeup water feed, as on the order of A gallons perhour per lineal foot of width, may be through a pipe 43 which extendsrearwardly from the front of the ventilator, as in FIG. 5, adjacent theright end thereof, as in FIG. 8, and then downwardly through the bracketplate 39 of FIG. 4. Water will flow from pipe 43 through the space atthat end of block 42 and also on top of block 42 to the space at theopposite end of the block.

Since the height of drain cube 32 is such that there is insufficientspace below the deflector plate 34 to accommodate the drain cube, arelatively short cover 44 is provided, which is contoured to fit overthe drain cube 32, as in FIG. 4, but is provided with end walls 45 whichextend downwardly to below deflector plate 34 and a lower flange 46which is in alignment with the lower edge of deflector plate 34. Cover44 also extends to the rear wall 19, for attachment thereto by bolts, asshown, extending through a rear, upwardly extending flange 47 of thecover.

After passage between segment 40 and front plate 17, the air drawn bythe suction fan will pass upwardly into a plenum chamber P of FIGS. 5and 8, in which the air will move from each end toward the center fordischarge through duct and thence into duct D for exhaust to theatmosphere.

For cleaning purposes, as in the manner described later, a hot waterfeed pipe 49 extends along the rear wall 19 within the channel structure41 and is provided with a series of spaced sprinkler type heads ornozzles 50, for spraying hot water toward the front plate 17 and theunderside of top plate 16, which will tend to be deflected onto thefixed baffle 25 and flow downwardly along the same, and also bedeflected against the air deflector plate 38. This hot water will alsoflow downwardly onto the cover 44 and water deflector plate 34 above thewater bath.

For safety purposes, in order to obstruct the passage of flames into theduct D, should a fire occur, a safety damper 51 is installed within theduct D, just above the plenum chamber P. The damper 51 may be merely aplate attached, as by U-bolts, to a pivot rod 52, the ends of which aremounted in bearings 53, shown in FIG. 3, installed in the opposite endwalls of the duct. The damper 51 is provided with a weight 54, as inFIG. 4, which extends the full length of one edge of the damper, so thatwhen released from the upright position of FIG. 4, the damper willimmediately swing to a closed position, shown in dotted lines in FIG. 4,with the weighted edge of the damper moving downwardly against an angle55 attached to the rear wall of the duct 20, and the opposite edge ofthe damper engaging an angle 56 attached to the front wall of the duct.In order to retain the damper in the open position, shown in full linesin FIG. 4, a fuse link cable extends around a pair of hooks 57 attachedto the damper adjacent each end and adjacent the edge opposite theweight, as in FIGS. 4 and 9. A pair of hooks 58 are attached to thefront wall 19 of the plenum chamber P, so as to be spaced apart fartherthan the hooks 57, with a cable 59 extending around one each of hooks 57and 58. The cables 59 are connected together between the hooks 58 by afuse link 60, which is of a conventional material which will melt at apredetermined fire hazard temperature, in order to release the cablesand permit the damper to close. Between hooks 57, the cables areconnected by a turnbuckle 61, so that the cables may be loosened, forplacement around hooks 57 and 58, and then tightened to hold the damperin open position. Normally, of course, the damper 51 will stay in itsopen position, perhaps for months at a time. However, the access plate18 may be removed to replace the fuse link and reset the cable, in theevent of fire from which the flames have melted the fuse link. Normally,of course, even in the event of a fire on the cooking equipment, flamessucked up into the ventilator will normally be extinguished by passagealong or through the churning water bath W.

In cleaning the ventilator of this invention, the operator is requiredtoclean manually only the front of upright plate 22 and its curl 23, theunderside of fixed baffle 25 and its arcuate portion 26, and the outsideof the adjustable baffle 27. Also, the operator may wish to reach overthe curl 23 and clean the inside of plate 22 above the water bath W. Allother surfaces are cleaned by a non-manual cleaning procedure, such asfollows. First, the operator dumps a supply of detergent or othercleaning liquid into the water bath, then permits the suction fan todraw the water containing the detergent solution up into the ventilatorthrough splashing and agitation of the water. As will be evident,thecleaning solution carried upwardly by the air stream will reach all ofthe surfaces which are reached by splashed water and water dropletsduring normal operation. After the detergent solution has been splashedabout on the inside of the ventilator, as for 30 minutes to 1 hour, the

, operator pushes the wash switch button 15 of FIG. 1,

which causes hot water to be supplied through pipe 43 at a rate severaltimes that of the normal makeup flow, such as on the order of 4 to 8gallons per minute, for a period of two minutes. This hot water replacesthe cold water in the water bath W, and the air flow is continued, sothat the air will splash hot water up against the underside of baffle 38and carry hot water droplets along the rear of section 26 onto the topof fixed baffle 25. When the wash switch 15 is first pushed, the coldwater metering valve, which normally supplies cold water for normal use,is shut off, and a hot water metering valve, which is set to produce theabove considerably higher rate or flow, as indicated, is turned on.While water is merely being fed into the water bath to replace the coldwater therein, the suction fan may continue running. Next, the operatorturns off the suction fan and pushes the wash switch 15 a second time,to supply hot water through a third valve to pipe 49 and to nozzles 50,which will spray toward the front plate 17, up against the top plate 16,and also into the duct section 20. In addition, water splashing fromfront plate 17 and top plate 16 will tend not only to splash againstrear plate 19, but also run downwardly along fixed baffle 25 and returnto the water bath. Of course, during this operation, excess water in thewater bath will tend to be drained by overflow into drain cube 32. Asnoted above, when the plenum wash nozzles are turned on, the suction fanshould be turned off. Thus, an electrical circuit which controls,through relays, the operation of this valve is interconnected with thefan control circuit, as described later, so that the hot water valve forpipe 49 cannot be turned on while the fan is running. As will beevident, the detergent and initial hot water washing operation can becarried out while cooking continues. However, when the suction fan isturned off for plenum washing, cooking should be discontinued.

As illustrated in FIGS. 10-12, a ventilator V of this invention, of thedowndraft type, may be mounted in any suitable manner above cookingequipment E of FIG. 12, such as a range, stove, broiler or the like, ora series of the same, with the side to side width of the ventilatorcorresponding to the width of the cooking equipment. The ventilator maybe provided with a hood H disposed above the cooking equipment E andhaving a shelf 10 on the top thereof and a front, depending flange 11'.A single side plate may form the end of both the ventilator V and thehood H, although the hood H may be furnished as a separate item ofequipment, with a side plate 130 of the ventilator and a side plate 13bof the hood, as in FIGS. 10 and 12 being separate but connected parts. Acontrol box C is conveniently mounted under the ventilator, although itmay be placed in any suitable position, while a housing 62 for a washswitch 15 may be mounted on the shelf of the hood, at one end. A lightswitch (not shown) may be used to turn on and off a light, such as ofthe fluorescent type, which extends across the underside of the shelf 10of the hood. The ventilator V is provided with a top panel 16' havingdepending flanges fitting over the end plates, an upper front plate 17of FIG. 14 and a back plate 19' of FIGS. 13 and 14. End plate 130 andback plate 19 extend down to a bottom plate 63 of FIGS. 14 and 17,having a rectangular opening located centrally thereof for a ductconnector 20 which is open at the top and at one end for connection, ata rectangular flange 64, with an outlet or exit duct D which leadsbeneath and then upwardly at one end of the ventilator to the flue of achimney. A suction fan of a conventional nature (not shown) is installedat an appropriate position in duct D. As before, the suction fan isturned on at all times, except at certain times during the washingcycle, although it may also be separately controlled. A drain pipe 65 isconnected to the opposite end of duct connector 20', adjacent the loweredge thereof.

The control box C may be provided with two compartments, in one of whichthe plumbing control valves are installed, and in the other of whichelectrical controls are installed, except the wash switch 15. As before,both the plumbing controls and the electrical controls are standardequipment.

A lower front plate 66, as in FIGS. 13 and 14, extends upwardly frombottom plate 63 to the lower edge of an upright plate 22, having anarcuate curl 23 at the top and extending across the front of theventilator in spaced relation to front plate 17. At its lower edge,plate 22 is connected to a bottom plate 24 of a water chamber. Asbefore, extending rearwardly and initially slightly downwardly from thelower edge of the front plate 17, is a baffle. 25 which continuesrearwardly and downwardly as an arcuate portion 26. An arcuate,adjustable baffle 27, having the same radius of curvature as fixedbaffle 25', but a planar segment 28 at its lower edge, is attached, asby bolts 29, to the fixed baffle. If desired, the bolts 29 may beinserted within holes in the fixed baffle 25 and extend through verticalslots in the adjustable baffle 27. For each installation, as indicatedpreviously, the position of adjustable baffle 27 is essentially fixed,depending upon the normal water level, as hereinafter described, and thetotal width of the ventilator and the cubic feet of air admitted, whichare drawn through the ventilator by the suction fan. In general, athroat section of lesser cross sectional area is formed between the endof planar segment 28 and the rear of upright plate 22, so as to increasethe velocity of the air flowing at this point, for a purpose describedbelow.

A water bath W having a normal level indicated by the dotted line 30 ofFIG. 15, and an upper contour during use, indicated by the full line 31of FIG. 16, is maintained in the lower portion of the water spacedetermined by the bottom plate 24, the upright plate 22, side plates 13aand a rear plate 67 of the water chamber. Plate 67 extends upwardly,then forwardly and upwardly in approximately a half circle, similarly toplate 38 of FIGS. 4 and 5. The normal level of the water bath W, as inFIG. 15, is determined by the height of a drain cube 32 which has anopen top and connects with a drain duct 68, which, as in FIG. 13,extends on the underside of bottom plate 24' and then downwardly alongplate 66 and thefront wall of duct 20', so that water overflowing intothe drain cube will flow into the bottom of duct 20' and out drain pipe65. As before, a frontally concave, arcuate deflector plate 34 extends,as in FIG. 17, from each end of the ventilator to the area of the draincube 32, along the lower rear of the water compartment, with deflectorplate 34 being attached, as before, to the bottom wall 24' by a seriesof lower tabs 35, as in FIG. 16, and by a correspondingly spaced seriesof upper tabs 36 to back plate 67, which is maintained in position byattachment to side plates 13a, or also by struts or bracketscorresponding to brackets 39 of FIGS. 4 and 5.

As before, the air stream pushes the water up against the deflectorplate 34', as well as agitating and whipping the surface of the water,to remove grease from the air stream, as well as condensed vaporproducts. Thus, the entire body of water W is forced by against thedeflector plate 34 and will overflow the upper edge of plate 34', tofall behind the plate and carry with it the retained grease andcondensed vapor products. The contour 31 of the water will become on theorder of that shown in FIG. 16, although the water will tend to surgeupwardly and downwardly as well during the agitation by the air.Additional water vapor or droplets will also enter the air stream andcondense or coagulate on the underside of the plate 67, as well as beingremoved when thrown against the front plate 17 due to the velocityimparted by a throat section, such as formed by a downwardly inclined,planar segment 40 at the upper end of plate 67. As before, a relativelyshort cover 44 is provided for drain cube 32, being contoured to fitover the drain cube 32 and provided with end walls 45, which extenddownwardly to or below plate 34, a lower flange 46', which is inalignment with the lower edge of deflector 34, and a flange 47' forattachment to the plate 67 by bolts, as shown.

The water feed for replenishing the water bath, due to evaporation oroverflow into drain cube 32, may be introduced at each end of theventilator, as through a pair of pipes 43 which extend rearwardly fromthe front of the ventilator, into the space between baffle 25 and plate67. Pipes 43 are supplied by a tube 69 which extends upwardly fromcontrol box C, as in FIGS. 14 and 17.

For cleaning purposes, as in the manner described later, a hot waterfeed pipe 49' extends along the upper rear corner of the ventilator, asin FIGS. 14 and 17, and is provided with a series of spaced sprinklertypeheads or nozzles 50, for spraying hot water onto the rear of baffleplate 67 and the inside of rear wall 19, as well as into the lowerplenum space F, for drainage from duct connector Another hot water pipe70 having a spaced series of nozzles 50 extends along the upper frontcorner of the ventilator, as in FIG. 14, for spraying hot water againstthe inside of plate 17 and onto baffle for deflection against the frontside of plate 67, with drainage along plate 67 and baffle 25 into thewater chamber. Hot water pipes 49 and 70 are supplied by a tube 71extending upwardly fron control box C, as in FIGS. 14 and 17, to rearpipe 49' and also across the top of the ventilator to front pipe 70.

For safety purposes, in order to obstruct the passage of flames into theduct D, should a fire occur, a safety damper 51 is installed within theduct connector 20' and the lower plenum chamber P. As before, damper 51may be merely a plate attached, as by U-bolts, to a pivot rod 52, theends of which are mounted in bearings (not shown) installed in theopposite end walls of the duct connector 20. The damper 51, as before,is provided with a weight 54, which extends the full length of one edgeof the damper, so that when released from the upright position of FIG.13, the damper will immediately swing to a closed position. Thus, theweighted edge of the damper will move downwardly against an angle 55attached to an appropriate wall of the duct connector 20, and theopposite edge of the damper will engage an angle 56' attached to theopposite wall of the duct connector. The unweighted edge of the damper51 is provided with a cutout to clear the drain duct 68. In order toretain the damper in the open position, as before, a cable extendsaround a pair of hooks 57 attached to the damper and a pair of hooks 58attached to the near wall of the duct connector 20. As before, a fuselink and a turnbuckle are interposed in the cable. A drain access plate21 may be installed over an opening in front plate 66, while an accessplate 18' may be installed over an opening in the rear wall of ductconnector 20', as in FIG. 13, for the same purpose as access plate 18 ofFIG. 1. Normally, of course, even in the event of a fire on the cookingequipment, any flames sucked up into the ventilator will tend to beextinguished by passage along or through the churning water bath W.

An electrical control system which may be used with either theventilator of FIGS. l-9 or the ventilator of FIGS. 10-17 is illustratedin FIG. 18, being interconnected with the duct fan previously described.Thus, a fan motor 73 may be controlled by a switch S which includescontacts 74 and 74, being supplied with current from power leads 75 and76 in a three-wire'system which includes a neutral line 77. In FIG. 18,the connection of the neutral line 77 to the fan motor 73 is not shown,for clarity of illustration; In addition to the wash switch 15, theelectrical controls include a relay R, a timing relay T and threesolenoid operated water control valves, including a valve 78 throughwhich cold water, as indicated, is supplied to the makeup pipe 43 ofFIGS. 4, 5 and 8 or the makeup tube 43 of FIGS. 13 and 14. The valve 78is adjusted to produce a relatively small rate of flow when open, asdescribed previously. Another solenoid controlled valve 79 supplies hotwater, as indicated and as from the normal hot water tap line, throughthe hot water feed pipe 49, to the pipe 43 or 43, being adjusted toproduce a higher rate of flow, for displacement of the cold water in thewater bath W or W by hot water, following addition of detergent to thecold water bath and normal agitation of the water bath by the air for ashort period of time, as indicated. Another solenoid controlled watervalve 80 also supplies hot water, as indicated, but at a much higherrate of flow, and to the plenum wash supply pipe 49 of FIGS. 4, 5 and 8or 49 of FIGS. 13, 14 and 17. In general, the electrical controls aresuch that the light switch 14 may be turned on at all times, the coldwater solenoid valve 78 and the hot water solenoid valve 79 may turnedon only when the fan motor 73 is running, while the plenum wash solenoidhot water valve 80 may be turned on only when the fan motor 73 is turnedoff. Thus, a hot" wire 81 is connected to the fan motor lead 76 andextends to the relay R, with afuse 82 being interposed therein, while abranch 83 thereof extends to the light switch 14. Return wire 84 fromthe light is connected to neutral lead 77.

. A wire 85 is also connected to the same fan motor lead 76, but beyondswitch contact 74, so that current will be supplied through wire 85 onlyif the fan motor is turned on. Wire 85 extends to the terminal of aswitch 86 of timing relay T, with a second fuse 82 interposed therein.From the normally closed contact of switch 86, a wire 87 extends to thecoil 88 of solenoid valve 78, the opposite side of coil 88 beingconnected to neutral line 77, as shown. Thus, when the duct fan isturned on, the solenoid valve 78 will be automatically opened and beginsupplying cold makeup water to the water bath in the ventilator. Abranch wire 89 leads from wire 85 to one end of the coil 90 of relay Rand thence to a switch 91 of the relay, while a wire 92 leads from theopposite end of the coil to the neutral lead 77. When the fan motor isturned on, the coil 90 of relay R will be energized, moving switch 91from the normally closed contact shown to its normally open contact. Aswitch 93 of relay R, to which wire 81 extends, will also be moved fromits normally closed .contact to its normally open contact. Thus, the

switches 91 and 93 will be moved to the dotted positions shown, when thecoil of relay R is energized. It will be noted that, when moved to itsnormally open contact, switch 91 will permit current to be suppliedthrough a wire 94 to a contact 95 of wash switch 15, which, however,remains open. Also, when switch 93 is in engagement with its normallyclosed contact, it will supply current through a wire 96 to anothercontact 97 of switch 15, while a branch wire 98 will also supply currentto a switch 99 of timing relay T. However, no flow of current can takeplace because switch is open, and there is no wire connected to thenormally closed contact of switch 99.

When the cleaning operations are begun and the detergent is poured bythe operator into the water bath W or W, in the respective form ofventilator shown, after agitation of the water bath and circulation ofthe water containing detergent up into the ventilator by the air, as forabout 30 minutes, the operator closes the wash switch 15, to start thereplacement of the cold water by hot water. Thus, when switch 15 isclosed, current will be supplied through wire 94 (switch 91 then beingin the dotted position) to contact 95 and its opposing contact 95' andthrough a wire 100 to a time delay coil 101 of relay T. When coil 101 isenergized, both switch 86 and switch 99 will be moved from itsrespective normally closed contact to its normally open contact. Whenthis occurs, the solenoid 88 of valve 78 will be deenergized, and thesolenoid 88' of valve 79 will be energized, through a wire 102 whichleads thereto from the normally open contact of switch 86. Althoughswitch 99 will also be 'moved to its normally open contact, which isconnected by a wire 103 with the solenoid coil 88" of valve 80, nocurrent will be supplied to coil 88", since switch 93 of relay R will bemoved to its dotted position, when the fan motor 73 is turned on. Thetime delay of relay T is set for a predetermined time, such as 2 or 3minutes, in order to permit the cold water in the water bath to bereplaced by hot water, after which the time delay relay is automaticallydeenergized, with switches 86 and 99 returning to their normally closedpositions. Then, the operator turns the fan motor 73 off, which willopen the switch contacts 74 and 74. This means that current is no longersupplied through wire 85 to coil 90 of relay R, which will also bedeenergized thereby, causing switches 91 and 93 to return to theirrespective normally closed contacts. in addition, the cessation ofcurrent flow through wire 85 will cause coil 88 of valve 78 to remaindeenergized, even though switch 86 of relay T returns to its normallyclosed contact. However, when switch 93 of relay R returns to itsnormally closed contact, the wire 81 connected to the motor lead 76ahead of contact 75 will supply current through switch 93 and wire 96 tocontact 97 of switch 15 and also through branch wire 98 to switch 99.Thus, after the fan is turned off and switch 15 is moved to closedposition a second time, time delay relay coil 101 will again beenergized, thereby moving switch 99 to its normally open contact andsupplying current through wire 103 to coil 88" of solenoid valve 80.This will cause hot water to be supplied to the plenum washing supplypipe 49 for the predetermined washing period, again determined by thetime cycle of relay T, at the end of which the time delay coil 101 willbe automatically deenergized and the switches 86 and 99 returned totheir normal positions. The operator may then turn on the fan motor 73which causes, through closing of the fan motor switch contact 75,current to be again supplied through wire 85, switch 86 and wire 87 tocoil 88 of solenoid valve 78, thereby turning on the cold water makeupwater and normal operation resumed.

It will be noted that the water droplets thrown out of the air stream byimpinging against front wall 17 of FIG. 5 or front wall 17 of FIG. 14will drain downwardly on the top side of fixed baffle 25 or 25',respectively. This water, as well as water splashed onto the top side ofthe fixed baffle 25 or 25, maintains the underside of the baffle at alower temperature, thereby minimizing the amount of grease or othercooking residue which will be burned or otherwise transformed by theheat from the cooking equipment and be more difficult to clean off. As aresult, the ventilator of this invention will require less labor tomaintain, in a clean condition, the underside of a baffle above thecooking area.

Although certain preferred embodiments of this invention have beenillustrated and described, it will be evident that other embodiments mayexist and various changes made without departing from the spirit andscope of this invention.

What is claimed is:

l. A grease extraction ventilator-connectable to a duct having means forproducing flow of an air stream into a front entrance space of saidventilator, through said ventilator and from said ventilator into saidduct, said air stream normally containing products of cooking in an areaadjacent said entrance space, such as smokeparticles, grease and thelike, said ventilator comprising a housing having:

a. a chamber below said front entrance space and having a front wall;

b. means for supplying water to said chamber; and

c. means for causing said air stream to engage and agitate said water,thereby causing said water and water vapor produced by said agitation totend to remove smoke particles, grease and the like from said airstream, including baffle means spaced from said front wall and formingthe rear wall of said front entrance space, said baffle means extendingrearwardly and downwardly to a point below the upper edge of said frontwall and then forwardly toward said front wall.

2. A grease extraction ventilator as defined in claim 1, including:

means for separating water moved by said air stream in the direction offlow of said air stream; and means for removing said separated watercarrying grease and the like from said chamber.

3. A grease extraction ventilator as defined in claim 1, wherein saidbaffle means includes:

an inlet baffle extending from a position forwardly and above the frontedge of said chamber, then curving rearwardly and downwardly to anadjustable baffie; and

said adjustable baffie including an arcuate rear portion and a planarfront portion extending toward said front wall of said chamber.

4. A grease extraction ventilator as defined in claim 3, wherein:

said upper edge of said chamber is provided with an arcuate curlgenerally concentric with the curve of said inlet baffle.

5. A grease extraction ventilator connectable to a duct having means forproducing flow of an air stream into a front entrance space of saidventilator, through said ventilator and from said ventilator into saidduct, said air stream normally containing products of cooking in an areaadjacent said entrance space, such as smoke particles, grease and thelike, 'said ventilator comprising a housing having:

a. a chamber below said front entrance space;

b. means for supplying water to said chamber;

c. means for causing said air stream to engage and agitate said water,thereby causing said water and water vapor produced by said agitation totend to remove smoke particles, grease and the like from said airstream, said means including an inlet baffie extending from a positionforwardly and above the front edge of said chamber, then curvingrearwardly and downwardly to an adjustable baffle, said entrance spacebeing formed between the underside of said inlet baffle and the upperedge of said chamber;

d. said adjustable baffle including an arcuate rear portion and a planarfront portion; and

e. a deflector baffle extending from the rear edge of said chamber abovethe water level therein and upwardly and forwardly in spaced relation tosaid inlet baffie to form a generally upwardly disposed passage abovesaid chamber.

6. A grease extraction ventilator as defined in claim 5, wherein:

said means for supplying water to said water chamber is adapted to feedwater into the space between the rear side of said deflector baffle anda wall which extends upwardly from the rear wall of said chamber.

7. A grease extraction ventilator as defined in claim 5, wherein:

said means for supplying water to said chamber is adapted to feed waterbetween the top of said inlet baffle and the underside of said deflectorbaffle.

8. A grease extraction ventilator as defined in claim 5, including:

a plenum chamber having a duct connection, said air stream flowingaround the upper edge of said deflector baffie and into said plenumchamber;

means for supplying heated water to displace water in said chamber; and

additional means for supplying heated water and directing such heatedwater into the space between said deflector baffle and the top of saidinlet baffie and also into said plenum chamber.

9. A grease extraction ventilator as defined in claim 5, including:

a plenum chamber above said deflector baffle and provided with aconnection for said duct.

10. A grease extraction ventilator as defined in claim 5, including:

a passage extending from above said deflector baffie and downwardly andrearwardly of said water chamber; and

a plenum chamber below said water chamber, said plenum chamber having aconnection for said duct.

11. A grease extraction ventilator as defined in claim 9, including:

a damper adapted to close the opening at said duct connection;

means for urging said damper toward its closed positron;

means for holding said damper in its open position;

and

temperature responsive means associated with said holding means andadapted to permit said damper to be closed in response to apredetermined temperature at said temperature responsive means.

12. A grease extraction ventilator as defined in claim 10, including:

a damper adapted to close the opening at said duct connection;

means for urging said damper toward its closed position;

means for holding said damper in its open position;

and

temperature responsive means associated with said holding means andadapted to permit said damper to be closed in response to apredetermined temperature at said temperature responsive means.

13. A grease extraction ventilator as defined in claim 5, wherein:

the upper end of said deflector baffle is provided with a downwardlyextending planar portion.

14. A grease extraction ventilator connectable to a duct having meansfor producing :flow of an air stream into a front entrance space of saidventilator, through said ventilator and from said ventilator into saidduct, said air stream normally containing products of cooking in an areaadjacent said entrance space, such as smoke particles, grease and thelike, said ventilator comprising a housing having:

a. a chamber below said front entrance space;

b. means for supplying water to said chamber;

c. means for causing said air stream to engage and agitate said water,thereby causing said water and water vapor produced by said agitation totend to remove smoke particles, grease and the like from said airstream; and

d. means for separating water moved by said air stream in the directionof flow of said air stream, including a plate curving upwardly insubstantially the rear portion of said chamber, the upper edge of saidplate being spaced from the rear wall of said chamber for overflow ofwater driven upwardly along said plate by said air stream and the loweredge of said plate being spaced above the bottom of said chamber for theflow of water from behind said plate to a position forwardly of saidplate.

15. A grease extraction ventilator as defined in claim 14, including:

overflow means behind and below the upper edge of said plate to permitwater overflowing said plate and carrying with it grease and the like tobe removed from substantially the top of said water behind said plate.

1. A grease extraction ventilator connectable to a duct having means forproducing flow of an air stream into a front entrance space of saidventilator, through said ventilator and from said ventilator into saidduct, said air streaM normally containing products of cooking in an areaadjacent said entrance space, such as smoke particles, grease and thelike, said ventilator comprising a housing having: a. a chamber belowsaid front entrance space and having a front wall; b. means forsupplying water to said chamber; and c. means for causing said airstream to engage and agitate said water, thereby causing said water andwater vapor produced by said agitation to tend to remove smokeparticles, grease and the like from said air stream, including bafflemeans spaced from said front wall and forming the rear wall of saidfront entrance space, said baffle means extending rearwardly anddownwardly to a point below the upper edge of said front wall and thenforwardly toward said front wall.
 2. A grease extraction ventilator asdefined in claim 1, including: means for separating water moved by saidair stream in the direction of flow of said air stream; and means forremoving said separated water carrying grease and the like from saidchamber.
 3. A grease extraction ventilator as defined in claim 1,wherein said baffle means includes: an inlet baffle extending from aposition forwardly and above the front edge of said chamber, thencurving rearwardly and downwardly to an adjustable baffle; and saidadjustable baffle including an arcuate rear portion and a planar frontportion extending toward said front wall of said chamber.
 4. A greaseextraction ventilator as defined in claim 3, wherein: said upper edge ofsaid chamber is provided with an arcuate curl generally concentric withthe curve of said inlet baffle.
 5. A grease extraction ventilatorconnectable to a duct having means for producing flow of an air streaminto a front entrance space of said ventilator, through said ventilatorand from said ventilator into said duct, said air stream normallycontaining products of cooking in an area adjacent said entrance space,such as smoke particles, grease and the like, said ventilator comprisinga housing having: a. a chamber below said front entrance space; b. meansfor supplying water to said chamber; c. means for causing said airstream to engage and agitate said water, thereby causing said water andwater vapor produced by said agitation to tend to remove smokeparticles, grease and the like from said air stream, said meansincluding an inlet baffle extending from a position forwardly and abovethe front edge of said chamber, then curving rearwardly and downwardlyto an adjustable baffle, said entrance space being formed between theunderside of said inlet baffle and the upper edge of said chamber; d.said adjustable baffle including an arcuate rear portion and a planarfront portion; and e. a deflector baffle extending from the rear edge ofsaid chamber above the water level therein and upwardly and forwardly inspaced relation to said inlet baffle to form a generally upwardlydisposed passage above said chamber.
 6. A grease extraction ventilatoras defined in claim 5, wherein: said means for supplying water to saidwater chamber is adapted to feed water into the space between the rearside of said deflector baffle and a wall which extends upwardly from therear wall of said chamber.
 7. A grease extraction ventilator as definedin claim 5, wherein: said means for supplying water to said chamber isadapted to feed water between the top of said inlet baffle and theunderside of said deflector baffle.
 8. A grease extraction ventilator asdefined in claim 5, including: a plenum chamber having a ductconnection, said air stream flowing around the upper edge of saiddeflector baffle and into said plenum chamber; means for supplyingheated water to displace water in said chamber; and additional means forsupplying heated water and directing such heated water into the spacebetween said deflector baffle and the top of said inlet baffle and alsointo said plenum chamber.
 9. A grease extraction ventilator as definedin claim 5, including: a plenum chamber above said deflector baffle andprovided with a connection for said duct.
 10. A grease extractionventilator as defined in claim 5, including: a passage extending fromabove said deflector baffle and downwardly and rearwardly of said waterchamber; and a plenum chamber below said water chamber, said plenumchamber having a connection for said duct.
 11. A grease extractionventilator as defined in claim 9, including: a damper adapted to closethe opening at said duct connection; means for urging said damper towardits closed position; means for holding said damper in its open position;and temperature responsive means associated with said holding means andadapted to permit said damper to be closed in response to apredetermined temperature at said temperature responsive means.
 12. Agrease extraction ventilator as defined in claim 10, including: a damperadapted to close the opening at said duct connection; means for urgingsaid damper toward its closed position; means for holding said damper inits open position; and temperature responsive means associated with saidholding means and adapted to permit said damper to be closed in responseto a predetermined temperature at said temperature responsive means. 13.A grease extraction ventilator as defined in claim 5, wherein: the upperend of said deflector baffle is provided with a downwardly extendingplanar portion.
 14. A grease extraction ventilator connectable to a ducthaving means for producing flow of an air stream into a front entrancespace of said ventilator, through said ventilator and from saidventilator into said duct, said air stream normally containing productsof cooking in an area adjacent said entrance space, such as smokeparticles, grease and the like, said ventilator comprising a housinghaving: a. a chamber below said front entrance space; b. means forsupplying water to said chamber; c. means for causing said air stream toengage and agitate said water, thereby causing said water and watervapor produced by said agitation to tend to remove smoke particles,grease and the like from said air stream; and d. means for separatingwater moved by said air stream in the direction of flow of said airstream, including a plate curving upwardly in substantially the rearportion of said chamber, the upper edge of said plate being spaced fromthe rear wall of said chamber for overflow of water driven upwardlyalong said plate by said air stream and the lower edge of said platebeing spaced above the bottom of said chamber for the flow of water frombehind said plate to a position forwardly of said plate.
 15. A greaseextraction ventilator as defined in claim 14, including: overflow meansbehind and below the upper edge of said plate to permit wateroverflowing said plate and carrying with it grease and the like to beremoved from substantially the top of said water behind said plate.